A couple weeks ago we asked mountain bikers to share their thoughts about the 27.5/650b wheel size and after crunching the numbers we put together this infographic to tell the story. We were shocked at the results and have come to the conclusion that not only are 27.5″ mountain bikes here to stay, they’re going to be even more popular than 29ers.

After talking about 27.5 for a couple years–will it, or won’t it take off–there are two trends emerging that lead us to the shocking conclusion that 27.5 will eventually take the largest share of the MTB market. The first trend is Trail/AM riding is becoming the type of riding most mountain bikers want to do (61% currently). Part of this is thanks to the improvement in equipment (lighter bikes) and also the fact that more aggressive–but rideable– trails are popping up all over the country (thanks IMBA!).

The second trend is toward specialized (lowercase) mountain bikes for different riding styles. We don’t know if it’s a powerful marketing message or just basic math driving this, but more than half of mountain bikers (51%) agree that 27.5″ mountain bikes are best for Trail/AM riding.

Add these two up and you get that the majority of riders like to ride Trail/AM and they agree that 27.5″ bikes are the best equipment for getting the job done. The number of mountain bikers who say the next bike they’ll purchase will be a 27.5″ (48%) confirms this.

Other interesting tidbits: 60% of mountain bikers think the standard should be called 27.5 (for mountain bikes, anyway). And those who have actually ridden a 27.5″ mountain bike don’t see the new standard as hype and are more likely to buy one than those who have not test ridden yet.

Thanks to all who contributed to this survey. What jumps out at you from the summary data?

What wheelsize would fatbikes fall into? The rims are 26 but the tire diameter is closer to 29. What about the 29+? Not to nitpick the data but the fatbike market is one of the largest growing market shares in mountain biking right now…and as someone who was looking at buying (another) fatbike during the survey period (then did), I didn’t know how to answer the questions.

I think it is interesting that 650b has been the standard in Europe for decades, but we as Americans want to call it 27.5 when it is closer to 27inches.

The margin of error of 4.3% makes this a flawed study at the 95% confidence interval, probably because the power is low with an N of 452. I hate statistics, BTW. As Mark Twain wrote: ‘There’s lies, damn lies, and there’s statistics…’. So how accurate was this poll?? Who knows. But I think the results are very, very interesting and fall in line with the gestalt of the mountain biking world.

I think what this poll doesn’t illustrate is that a lot of would-be-26ers are being driven out of the market by the overwhelming push for 650b in the market…so they forced to consider this bike even if they don’t want to.

Fatbikes are definitely fast growing but they will never have the impact 27.5 will. Based on anecdotal data, Fatbikes are like a 4th or 5th bike for a lot of people and that’s why we asked about people’s primary bike and mode of riding. Sounds like you may be part of the 1%. 🙂

As far as the margin of error goes, it actually indicates that many of these results are accurate. For example, the split between calling the new wheel size 650b or 27.5 is separated by 20 percentage points, well outside the margin of error which means we can say with 95% confidence the result (that more people like the name 27.5) is correct. Same goes for most of the key stats we’ve included. [We left off other measures that were not statistically significant, for example gender and geographical splits.]

It’s kind of sad to see the decline of 26″ wheels. I probably won’t even really have a choice but to get a 27.5er for my next bike (not saying that’s a bad thing), but that probably won’t be for a while since I don’t have the money for a new bike and don’t really need one.

They are trying to get people to call it “27 five.” I strongly urge readers to resist this foolish jargon, and to use either the traditional “650B” designation, or, better yet, the internationally-standardized “584 mm” designation.

We didn’t include 584 mm as a third option but somehow I don’t think it would have garnered many votes. 🙂

In my humble opinion, the 27.5” size in reality is MUCH closer to 27”. Just for the sake of simplification, they should just call it 27”. The 650b designation is a European metric road bike designation. Mountain bikes were popularized and developed first in America (hence the non-metric designation of 20”, 26”, and 29” for most MTB tires).

I’m not really sure I agree with all this. I actually think body geometry has something to do with wheel choice. Having experience with all options, I always gravitate back to the big wheels. Maybe 6′ 3″ is what makes me do this. But I think I speak for my whole riding group, that we all like the 29er the best. And…we’re not all tall. We ride everything except DH and everyone has made the transition to 29, enough have tried the 27.5 and turned around also. Food for thought….

I ride a 26er (all mountain rider) and believe I will be forced someday to get a 27.5″ like it or not. However, I rented a MTB for a 8 day off road TransAlp tour in August and ended up with a Scott Genius 710 650B. It rode very, very nicely. Climbed great and handled well downhill and on the rocky terrain. Seemed to roll better than the other 7 riders I was with also, including some 29ers (and I was probably the lightest rider). However, when returning home to my 26er (Radon QLT Race AM) it seemed more nimble and quick and I didn’t miss the Scott. Of course, at that point I was without the 8 kg backpack and probably the best shape of my life. So, I would buy 650B if forced but just don’t get all the hype. Seems like the suppliers are trying to sell new wares.

I love my 26er FS bike. Parts like forks, tires, and wheel sets are so inexpensive and readily available compared to 29er and 27.5er parts. I will enjoy and use up my 26er. By the time I need to replace it, the 27.5er and 29er parts will be much more commonly available and cheaper.

I rode a 700c (same wheel size as a 29er) rigid frame bike for many years on technical trails. I also test rode a 27.5er and a 29er on a nicely built up back lot behind a bike shop. The difference between my 26er and that 27.5er was not much (27.5er was had a slight edge in my opinion). The 29er felt like driving a big block V8 musclecar. Crazy fast plow through attitude but not as nimble in the tight and twisty sections.

Honestly, I think that most MTB riders have or had 26ers and want to try out 29ers, so sales of 26ers are way down and getting worse every day. I also think that 27.5ers have higher profit margins compared to 26ers for the bike shops. Eventually 26ers will be mostly for lowest-end spec bikes and DH only.

Having ridden all three types, 26″, 27.5″, and now a 29″, I’d have to say each bikes has it’s own merits per the rider and the terrain. To say 26″ bike will go out and be replaced by 27.5″ isn’t entirely true. 26″ is still a more widely owned market, and it would be a long time before it was phased out. As a bike mechanic, 85% of the MTB’s I see are 26″ bikes.
As to my personal opinion, 26″ is preferable to 29″ when it comes to sharp corners and tight spaces, but if I know a trail has lots of large obstacles I take the 29er. 27.5″ is great for rough trails that have some sharp corners. Again though, it all comes down to technical details like wheelbase and geometry.